If you used Google on Monday, you may have noticed the Google doodle on its homepage included an image of a man with glasses wearing a medal around his neck. That man was Fred Toyosaburo Korematsu, a civil rights activist who stood up against the U.S. government’s internment of Japanese-Americans during World War II.

How appropriate that Monday was Korematsu’s birthday. Google’s portrayal of him among red, white and blue letters was befitting following a weekend of chaos over President Donald Trump’s recent executive order. Last Friday, President Trump closed America’s doors to Syrian refugees indefinitely, to all refugees for 120 days, and to citizens of seven Muslim-majority countries for the next 90 days.

What ensued over the weekend was mass confusion at airports as well as heartbreak and fear for those across the world whose plans to return home or find refuge here were halted.

Fred Toyosaburo Korematsu was among the nearly 120,000 residents and U.S. citizens of Japanese ancestry removed from their homes and incarcerated in military-run camps under the guise of national security, following a long history of legal discrimination against Asians and Asian Americans. This painful chapter in American history is emblematic of the short memories too many in this country have when it comes to immigration.

The city of Salem is blessed by a rich diversity of people from all over the world. Its history is bound up intimately with that of immigrants who fled war, famine and religious persecution seeking refuge and opportunity. The 17th century English immigrants who settled in what was the established village of Naumkeag were economic and religious migrants, and they claimed a stake on land that indigenous inhabitants had lived on for centuries.

Salem’s prominence and wealth since that moment has depended on personal, economic and political engagement with the world at large, existing within a nation whose greatness was built on the energy, insights, and diversity of migrants from all continents.

And yet, this nation of immigrants has a troubling past of discrimination and exclusion. In the mid-19th century, the arrival of Irish and German Catholics fueled nativist agendas. By the 1880s, exclusion of Chinese immigrants had become the law of the land. The Immigration Act of 1924 effectively ended Asian immigration and severely restricted immigration from Southern and Eastern Europe. In its wake, wide swaths of people from around the world were denied entry because of place of origin, ethnicity, religion or politics.

In 1939, in the name of national security, the U.S. turned away the ship The St. Louis, returning its nearly 1,000 passengers — almost all Jewish — to Germany where many were killed in the Holocaust. Just three years later, President Franklin Delano Roosevelt issued Executive Order 9066 and this nation interned its own citizens and long-term residents.

The United States has since proclaimed the inhumanity of World War II-era internment and, citing “race prejudice, war hysteria, and a failure of political leadership” as motivations for the act, formally apologized to survivors and their families. Many Americans mistakenly believe that this troubled past is behind us.

Sadly, the lessons of our history are all too relevant today. Those who fail to see this should take note that Executive Order 9066 did not specifically call for the internment of Japanese-Americans. Rather, it gave the military permission to remove from a certain area of the country anyone who was deemed a threat to national security, creating a legal framework to discriminate against those citizens and residents of Japanese descent. Bear this in mind as we are assured that the ban on refugees and citizens of Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen is a mere matter of national security.

Those who shudder at the shameful actions of the past should make their voices heard today. Write to your senators and members of Congress, speak with and learn from other members of your communities, engage in peaceful demonstrations to show the world that you will stand up for diversity, pluralism and justice for all.

The America so many of us know and love was on full display in Boston’s Copley Square on Sunday. The thousands of protesters from all walks of life varied in many ways, such as age, gender, race, ethnicity and religion. There was tremendous beauty in both our differences and in the common threads that brought us there. Together, we rallied in defense of the principles that built this country, thankful to those who have long fought to defend them on the streets and in courtrooms as well as on battlefields, and determined to learn from—not repeat— the past.

Elizabeth Duclos-Orsello, PhD, is a Fulbright Scholar and chair of the interdisciplinary studies department at Salem State University, where she coordinates and teaches in the American studies program.